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ENGINE DISASSEMBLY

Well you have your engine out of the car and ready to take apart. Proper engine disassembly is every bit as important as proper engine assembly ! Once again, your most important tool could be your digital camera, especially if you are working on an unusual engine. Take as many pictures as possible before and during the disassembly process.

The first thing you need to do is put it on your engine stand so that you can work on it easier than with it sitting on the garage floor.

Hint: Adjust the head of the engine stand so the center of rotation is in line with the camshaft on V-8 engines. This seems to pretty well balance the engine so you can rotate it on the stand without it wanting to flop over.

After you get it on the stand, drain the coolant and oil if you didn’t do this before pulling the engine from the car or truck. Most people start thier engine disassembly from the top, removing the intake manifold, valve train and cylinder heads first. Then flip the engine over and take the bottom end apart.

Hint: Pay careful attention to how bolts and nuts “feel” as you loosen them. If a bolt is loose, it could be a clue as to why you had an engine failure.

Hint: SAVE EVERYTHING ! Until you are completely finished with your engine repair. The old, worn out parts can give many clues to help you and your machine shop determine what went wrong with your engine and how to best repair it. Also, you should compare all of your new parts to the old ones to make certain that they are correct before reassembling the engine.

Before you loosen the connecting rod bolts, see if the rods are numbered. Most Ford engines will have numbers from the factory, but most GM engines do not. If you are going to number the rods with a set of number stamps, it is best to do it while they are still bolted together on the crankshaft. If you wait until you have the rods out of the engine, you will risk distorting the big end bore when you stamp the numbers.

Main bearing caps also need to be numbered during engine disassembly so they will be installed in the correct position when the engine is reassembled.

After removing the connecting rod nuts, you can remove the rod caps and push the pistons out of the engine from the bottom. Please do not hammer on the ends of the rod bolts to get the cap off ! This usually pushes the bolt out of the rod and affects the alignment. I will usually tap on the side of the rod cap with a brass hammer to get it loose. Make sure to put some rod bolt covers or small lengths of rubber hose on the bolts so that you don’t hit the crankshaft when removing the pistons. You can use a long piece of wooden dowel to push the pistons out from the bottom without hurting them.

Ridge reamer ???? FORGET IT !!! A lot of times there will be a pretty big wear ridge at the top of the cylinder bore where the pistons rings stop their travel. There is a tool called a ridge reamer that is designed to remove this ridge. PLEASE DO NOT USE IT !!!! Most every time that a customer has brought me an engine block that has been “ridge reamed”, the block has to be bored to a much larger oversize than necessary because of the Ridge Reamer. I have seen some blocks that were ruined beyond repair by this tool.

I have never seen an engine that the pistons would not come out because of the wear
ridge.

Taking the camshaft out of the block is a lot easier if you put a long bolt into one of the holes in the front of the cam and use it as a handle. Try to be careful not to scar up the camshaft bearings as you remove the camshaft, especially if there is a chance you will not be replacing them.

It helps to lay all of the parts out in order on a workbench. That way you can examine them to see what will need to be replaced and what failed.

Once your engine disassembly is done, you can truck the pieces off to your automotive machine shop to see what repairs will be needed and which parts will need to be replaced.